Onkyo DX-1400

Onkyo's humble entry-level CD player that ended up in more tweakers' workshops than showrooms.

Overview

The DX-1400 was Onkyo's entry-level compact disc player, and the specification sheet reads like a checklist of early-CD engineering: eight-times-oversampling digital filters paired with dual 18-bit linear digital-to-analog converters, the two converter chips individually calibrated according to HiFI-Stereo (February 1991, p.18). That same report lists twenty-track programming, CD-3 compatibility, and a three-mode time display among the operating features. For a budget deck, the digital section was taken seriously enough that the converters got their own calibration step — the kind of detail that usually shows up further up a manufacturer's line.

What makes the DX-1400 interesting to collectors now has less to do with what Onkyo shipped and more to do with what owners did to it afterward. The player turns up repeatedly in the pages of the DIY audio press as a modification platform, and the reason is visible once the lid comes off: the unit carries a pair of PCM61P converter chips alongside a Yamaha YM3433 digital filter. That filter is the same part found in the Audio Alchemy DAC-in-a-box, a detail that led at least one owner to conclude the digital half of the player was "probably pretty decent" and therefore worth hacking. The converters themselves are 16-pin parts rather than the 28-pin Burr Brown chips (PCM58P and PCM63P) that dominated the tube-output modification literature of the period, so anyone following those published recipes had to reverse-engineer the pinout first.

The modifications owners actually performed are well documented. One widely circulated approach replaced the stock solid-state output stage with a tube gain stage, tapping the DAC's current output through a resistor functioning as an I/V converter and feeding the resulting signal straight to the grid of the tube. A simpler variant swapped the stock I/V stage for a resistor converter feeding a 6922 mu-stage output amplifier — that configuration appears in the front-end list for a 1996 vintage speaker comparison, where the modified DX-1400 served as the source component. Owners also report damping the chassis with plumber's putty, shielding the digital chips, and beefing up the power supply, all in pursuit of a quieter, less "digital" sound. None of this is required to enjoy the player; it is simply what happens when a cheap, competent transport lands in the hands of people who can't leave a circuit board alone.

Reception in the period press was modest and matter-of-fact. HiFI-Stereo (February 1991, p.18) treated the DX-1400 as a new-product entry rather than a review subject, describing the oversampling and dual-converter architecture without editorial verdict. Audio (October 1990, p.164) listed compact disc players and D/A converters in a buyer's directory that same season, the sort of roundup where a budget Onkyo would sit alongside far more expensive converters. The player's reputation, in other words, was not built on magazine praise — it was built on the fact that it was cheap, it worked, and it was easy to open up.

That last quality is the whole story for collectors today. A stock DX-1400 is a perfectly serviceable early-90s CD player, but the ones that matter to the hobby are the modified examples — the tube-output conversions, the recapped power supplies, the damped chassis. Original condition examples surface occasionally, and modified ones surface with varying degrees of competence; anyone buying should look closely at the workmanship, because a poorly executed output-stage modification is worse than no modification at all. The digital filter and converter pairing is the reason the deck earned its following, and it remains the reason a DX-1400 is worth pulling off a shelf today.